A patient with distinct dissociative and hallucinatory fugues

Summary

A 62-year-old man presented with a history suggesting both dissociative fugue and a distinct fugue-like hallucination. The
dissociative fugues included unplanned travel, loss of personal identity, inability to recall his past and amnesia for the
fugue interval. The subjective fugues consisted of a stereotyped hallucination wherein he would travel to a social gathering
place, meet his ‘imaginary friends’ and engage with them in conversation. He experienced the subjective fugues as if they
were real, recognised them as hallucinations when he was normally conscious, and remembered them in great detail. A hallucinatory
fugue episode occurred during video-EEG monitoring. The patient engaged in semipurposeful behaviour for which he had no memory,
and the EEG demonstrated waking rhythms. Epilepsy, sleep disorder, factitious disorder and malingering were excluded from
the differential diagnosis, leaving a patient with both dissociative and hallucinatory fugues, likely made possible by remote
traumatic injury to limbic, arousal and motor circuits.